Stainless Steel 316 Capillary Tubes Manufacturer & Supplier
Amardeep Steel Centre produces and stores high-precision stainless steel 316 capillary tubes, which have been tailored to be used in applications where there is a need for micro-bore precision and effective anti-corrosion properties. These tubes can be obtained as seamless or welded, in accordance with ASTM A269 and ASTM A213 requirements. The products boast of outer diameters from 0.3 to 10 mm, as well as wall thicknesses starting at 0.08 mm. Moreover, with 2%-3% molybdenum content in grade 316 steel, advanced protection against pitting corrosion, crevice corrosion and chloride attack in aggressive environments is ensured.
What Are Stainless Steel 316 Capillary Tubes?
Capillary tubes are small-bore, thin-walled precision tubes held to extremely tight tolerances on OD, ID, and wall thickness and are typically used as flow restrictors in refrigeration circuits, pressure-sensing lines in transmitters and gauges, and thermocouple or sensor sheathing. The bright annealed or pickled finish on both the ID and OD keeps the bore free of scale and oxide, which matters directly for flow accuracy since even minor bore restrictions or debris can throw off pressure readings or block fine-bore lines. Grade 316's molybdenum content also lets these tubes hold up in high-temperature and chloride-exposed process lines up to roughly 870°C, and they're supplied coiled for continuous runs through instrument panels or cut to straight lengths for fixed installations.
Technical Data
Stainless Steel 316 Capillary Tube Specification
| Specification | Detail |
|---|---|
|
Standard |
ASTM A213, ASTM A269, ASTM A312, EN 10216 5 |
|
Grade |
SS 316, UNS S31600, Werkstoff 1.4401 / 1.4436, JIS SUS 316 |
|
Outer diameter |
0.3 mm to 10 mm, larger sizes on request |
|
Wall thickness |
0.08 mm to 1.5 mm |
|
Length |
Cut length, fixed length, single random, double random or continuous coil |
|
Type |
Seamless or welded |
|
Form |
Round, straight or coiled |
|
End finish |
Plain end or bevelled end |
|
Surface finish |
Bright annealed, pickled, polished or electropolished |
|
Certification |
EN 10204 3.1 Mill Test Certificate standard, 3.2 on request |
Chemical Composition of Stainless Steel 316 Capillary Tube
| Grade | UNS | C max | Mn max | Si max | P max | S max | Cr | Ni | Mo |
|---|---|---|---|---|---|---|---|---|---|
|
TP316 |
S31600 |
0.08 |
2.00 |
1.00 |
0.045 |
0.030 |
16.0 to 18.0 |
10.0 to 14.0 |
2.0 to 3.0 |
Stainless Steel 316 Capillary Tube Mechanical Properties
| Property | Value |
|---|---|
|
Tensile strength, minimum |
515 MPa (75000 psi) |
|
Yield strength, 0.2 percent proof, minimum |
205 MPa (30000 psi) |
|
Elongation in 50 mm, minimum |
35 percent |
|
Hardness, maximum |
95 HRB |
|
Solution annealing temperature |
Approximately 1040 C, followed by rapid cooling |
|
Maximum continuous service temperature |
Approximately 925 C in oxidising atmospheres |
Equivalent Grades for Stainless Steel 316 Capillary Tube
| Standard | UNS | Werkstoff | AFNOR | EN name | JIS | Old BS |
|---|---|---|---|---|---|---|
|
SS 316 |
S31600 |
1.4401 / 1.4436 |
Z7CND17 11 02 |
X5CrNiMo17 12 2 |
SUS 316 |
316S31 / 316S33 |
Stainless Steel 316 Capillary Tubes Dimension Chart
| Outer diameter (mm) | Wall thickness (mm) | Inner diameter (mm) |
|---|---|---|
|
0.30 |
0.08 |
0.14 |
|
0.50 |
0.10 |
0.30 |
|
0.80 |
0.15 |
0.50 |
|
1.00 |
0.20 |
0.60 |
|
1.50 |
0.25 |
1.00 |
|
2.00 |
0.30 |
1.40 |
|
3.00 |
0.50 |
2.00 |
|
4.00 |
0.50 |
3.00 |
|
6.00 |
1.00 |
4.00 |
|
8.00 |
1.00 |
6.00 |
|
10.00 |
1.50 |
7.00 |
Dimensional Tolerances for Stainless Steel 316 Capillary Tube
| Size range | Outer diameter tolerance | Wall thickness tolerance | Length tolerance |
|---|---|---|---|
|
Up to 2 mm OD |
Plus or minus 0.02 mm |
Plus or minus 10 percent |
Plus 3 mm, minus 0 mm |
|
2 mm to 6 mm OD |
Plus or minus 0.05 mm |
Plus or minus 10 percent |
Plus 3 mm, minus 0 mm |
|
6 mm to 10 mm OD |
Plus or minus 0.08 mm |
Plus or minus 10 percent |
Plus 3 mm, minus 0 mm |
Key Industrial Applications
- High Performance Liquid Chromatography (HPLC)
- Medical Probes & Surgical Tools
- Pressure Transmitters & Impulse Lines
- HVAC Expansion Valves
- Offshore & Marine Instrumentation
To learn more about how small-diameter components function under severe conditions, read our guide on Industrial Applications Guide.
Get a Competitive Quote for Stainless Steel 316 Capillary Tubes
Amardeep Steel Centre supplies stainless steel 316 capillary tubes with complete documentation, including EN 10204 3.1 Mill Test Certificate. Request a quote or contact our Mumbai office with your outer diameter, wall thickness and quantity.
Frequently Asked Questions
What is the difference between SS 316 capillary tubes and normal SS 316 tubes?
A capillary tube is generally under about 10 mm outer diameter with a thin wall and very tight dimensional tolerance, built for accurate low-volume flow in sensing and measurement duty. A normal tube or pipe is larger, carries a heavier wall thickness for the same duty and is intended for general fluid or gas transport rather than precision measurement.
What sizes are available for SS 316 capillary tubes?
We stock outer diameters from around 0.3 mm up to 10 mm, with wall thicknesses from about 0.08 mm to 1.5 mm, in cut lengths or continuous coil, across both seamless and welded construction. Larger sizes and custom combinations are available on request.
What is the difference between seamless and welded SS 316 capillary tubes?
Seamless tube is drawn from a solid billet with no weld line, giving a more uniform wall, a smoother bore and a higher pressure rating for a given size. Welded tube is formed from strip and welded before being drawn to final size, and it is a more economical option that suits the great majority of instrumentation and sensing duty.
Which industries commonly use SS 316 capillary tubes?
Medical and surgical instruments, chromatography and laboratory equipment, instrumentation and pressure sensing, high-pressure hydraulic lines, chemical and petrochemical processing, marine and offshore applications, heat exchangers, and aerospace and defence all rely on SS 316 capillary tube where chloride resistance is important.
What standards govern SS 316 capillary tube manufacturing?
ASTM A213, ASTM A269 and ASTM A312 are the standards most commonly specified for austenitic capillary and instrumentation tube in grade 316, with EN 10216- 5 also available for European projects, covering both seamless and welded construction routes.
Can SS 316 capillary tubes be supplied in coil form?
Yes. Coil form is common for long instrumentation runs and reduces the number of joints in a system, while straight cut lengths are typically used for fabrication into gauges, manifolds and shorter assemblies. Tell us your intended use, and we will recommend the right form.
Related Products
316 family: SS 316 Pipes & Tubes, SS 316 Micro Tubing, SS 316 Coil Tube Manufacturer, SS 316 Flanges, SS 316 Buttweld Fittings
